After a big rain it seems my 986 has electrical trouble. When I turn on high beams, the radio turned off for a second then back on by itself. The headlights dim in time to the turn signals, and brake lights. Also it seems the computer turns off and comes back on when pushing the brake pedal. Horn has never worked, not even alarm horn. Help...

 

I know you can get a lot of strange electrical problems from a falty ignition switch. You may want to look into that - its pretty cheap to do and can be done yourself. Also the horns are most likely just dead - also cheap to replace around 25 bucks for both horns shipped to you door and also a DIY job.

 

Thank you. I just replaced the ignition switch on the end of the stalk 2 weeks ago. I have my maf disconnected. Maybe that's some of my grief?

 

Rain? Uh oh...

Better check under your driver seat and hope the floor is dry. Also, make sure your drains (in the frunk by the battery, and rear under the clamshell) are not clogged.

Additionally, use a DMM and check the voltage across your battery terminals. Should be ~ 12.6 when car is off and b/w 13-14 while motor is running to hopefully exclude any alternator issues.

Good luck

 

Burg's right - check the floors under the seats.

My car started acting stupid when the alternator started to fail. Might want to check that out.

 

As it turns out, floor was wet, drains were clogged and... The drain pan behind right seat was torn when the tension rod for the top snapped and bent into the drain pan. I tried to repair it with neoprene glue.

 

Clean your ground points as well some are under seat. Use a dielectric grease on multipin connectors, they like to corrode.